GROUP!s in MY Repeat Evaluations

[hostilefork]

The current implementation technique of MY means this test fails, because count is 2

count: 0
o: make object! [x: null]
nuller: function [y] [return null]
o.(count: count + 1, first [x]): my nuller
did all [
    o.x = null
    count = 1
]

The GROUP! is executed twice, due to the MACRO-based implementation.